A technique referred to as “positive airway pressure” (PAP) allows monitoring respiration of a patient who suffers from respiratory disorders, such as, for example, apnea or hypopnea. In accordance with this technique, the patient receives a pressurized airflow via a mask, preferably while the patient is asleep. An airflow source, which is typically in the form of a ventilation unit, produces the pressurized airflow. The pressurized airflow typically comprises breathable air, which may optionally be oxygen-enriched, or have any other suitable composition. The airflow source is adjusted in accordance with an airflow pressure that a physician has prescribed. An airflow sensing device is coupled between the airflow source and the mask. The airflow sensing device provides an indication of a rate at which the airflow traverses the airflow sensing device. A processor may produce monitoring data on the basis of the indication that the airflow sensing device provides.
WO 9945989 describes a system for treatment of a medical disorder such as obstructive sleep apnea or congestive heart failure. The system comprises a flow sensor that determines a flow rate of pressurized gas delivered to a patient. The system delivers a pressure to the patient that is a function of this patient flow rate.